1216611010066 has 4 divisors (see below), whose sum is σ = 1824916515102. Its totient is φ = 608305505032.

The previous prime is 1216611010063. The next prime is 1216611010103. The reversal of 1216611010066 is 6600101166121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 613613722225 + 602997287841 = 783335^2 + 776529^2 .

It is not an unprimeable number, because it can be changed into a prime (1216611010063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304152752515 + ... + 304152752518.

Almost surely, 2^{1216611010066} is an apocalyptic number.

1216611010066 is a deficient number, since it is larger than the sum of its proper divisors (608305505036).

1216611010066 is an equidigital number, since it uses as much as digits as its factorization.

1216611010066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608305505035.

The product of its (nonzero) digits is 2592, while the sum is 31.

Adding to 1216611010066 its reverse (6600101166121), we get a palindrome (7816712176187).

The spelling of 1216611010066 in words is "one trillion, two hundred sixteen billion, six hundred eleven million, ten thousand, sixty-six".